By master controller and PQS1 Series Magnetic control panel consisting of a control circuit for controlling the bridge crane hoist lifting mechanism of control. Master controll
er handle SA has seven positions: In addition to the zero position, there are three lifting gear, lift speed can be obtained in three different degrees; there are three drop block, the second block for the single-phase brake down first 3 block is forced down if it is the weight of the transition to a system for generating motion decline; first stop only when pulled from the first block of the first block 2, 3, in order to pull down the brake for fall, nowhere else. Zero parking brake when YA first action, the motor delay o. 65s after power to prevent stopping power generated with heavy slip hook. Commutation of the relay KTi pull delay is 0.11N0.16 s, off delay is 0.15 ~ 0. 2s, the main purpose is to extend contacts for access time, to avoid phase short circuit.